Three-dimensional papermaking belt

ABSTRACT

The present invention relates to belts useful in the manufacture of paper products, such as tissue paper. Particularly this invention relates to a belt used in a through-air drying process for making tissue products, and more particularly to an additively manufactured belt having a particular pattern thereon which imparts properties to tissue products manufactured therewith.

RELATED APPLICATIONS

The present application is a divisional application and claims priorityto U.S. patent application Ser. No. 16/369,051, filed on Mar. 29, 2017,which is a divisional application of U.S. patent application Ser. No.15/326,514, filed on Jan. 16, 2017, now U.S. Pat. No. 10,280,563, whichis a national-phase entry, under 35 U.S.C. § 371, of PCT PatentApplication No. PCT/US15/61035, filed on Nov. 17, 2015, which claimsbenefit of U.S. Provisional Application No. 62/084,260, filed Nov. 25,2014, all of which are incorporated herein by reference.

BACKGROUND

The present invention relates to the field of paper manufacturing. Moreparticularly, the present invention relates to the manufacture ofabsorbent tissue products such as bath tissue, facial tissue, napkins,towels, wipers, and the like. Specifically, the present inventionrelates to improved fabrics used to manufacture absorbent tissueproducts having background regions optionally bordered by decorativeelements, methods of tissue manufacture, methods of fabric manufacture,and the actual tissue products produced thereby.

In the manufacture of tissue products, particularly absorbent tissueproducts, there is a continuing need to improve the physical propertiesand final product appearance. It is generally known in the manufactureof tissue products that there is an opportunity to mold a partiallydewatered cellulosic web on a papermaking fabric specifically designedto enhance the finished paper product's physical properties. Suchmolding can be applied by fabrics in an uncreped through-air driedprocess as disclosed in U.S. Pat. No. 5,672,248 or in a wet pressedtissue manufacturing process as disclosed U.S. Pat. No. 4,637,859. Wetmolding typically imparts desirable physical properties independent ofwhether the tissue web is subsequently creped, or an uncreped tissueproduct is produced.

However, absorbent tissue products are frequently embossed in asubsequent operation after their manufacture on the paper machine, whilethe dried tissue web has a low moisture content, to impart consumerpreferred visually appealing textures or decorative lines. Thus,absorbent tissue products having both desirable physical properties andpleasing visual appearances often require two manufacturing steps on twoseparate machines. Hence, there is a need for a single step papermanufacturing process that can provide the desired visual appearance andproduct properties. There is also a need to develop a papermanufacturing process that not only imparts visually discernable patternand product properties, but which does not affect machine efficiency andproductivity.

Previous attempts to combine the above needs, such as those disclosed inInternational Application Nos. PCT/US13/72220, PCT/US13/72231 andPCT/US13/72238 have utilized through-air drying fabrics having a patternextruded as a line element onto the fabric. The extruded line elementmay form either discrete or continuous patterns. While such a method canproduce textures, extrusion techniques are limited in the types of linesthat may be formed resulting in reduced permeability of the through-airdrying fabric. The reduced permeability in-turn decreases dryingefficiency and negatively affects tissue machine efficiency andproductivity.

As such, there remains a need for articles of manufacture and methods ofproducing tissue products having visually discernable patterns withimproved physical properties without losses to tissue machine efficiencyand productivity.

SUMMARY

The present invention provides a papermaking belt having a threedimensional design element formed by apertured elements or a pluralityof spaced apart protuberances that may satisfy one or more of theforegoing needs. For example, a papermaking belt of the presentinvention, when used as a through-air drying fabric in a tissue makingprocess, produces a tissue product having a substantially uniformdensity as well as optionally possessing visually discernible decorativeelements. Therefore, in certain aspects the present invention provides apapermaking belt manufactured in-part using solid freeform fabrication(SFF) or layer manufacturing (LM) techniques, such as 3-D printingtechniques. The resulting papermaking belt comprises a supportstructure, such as a continuous woven papermaking fabric, having anapertured three dimensional element disposed on the paper contactingsurface thereof.

In other aspects the present invention provides a method ofmanufacturing a papermaking fabric by SFF. Solid freeform fabricationmay be used to form a fabric having a three-dimensional element disposedon the sheet contact surface of a supporting structure wherein theelement is formed layer by layer, in a stepwise fashion, out of aflowable material that is subsequently solidified so as to withstand therigors of the papermaking process, such as high temperatures andhumidity. Thus, in one aspect layers of flowable material are laid down,stepwise, in droplet form from an inkjet printing head onto a supportstructure, such as a woven papermaking fabric, in the desired locationsand are each solidified as they are laid down.

In another aspect the present invention provides a method ofmanufacturing a papermaking belt comprising the steps of feeding amaterial from at least one nozzle onto a support structure, such as awoven papermaking fabric having a paper contacting and machinecontacting surface, wherein the nozzle is moveable along a translationalaxis with respect to the support structure and the spacing between thenozzle and the support structure is adjustable, and wherein flow throughthe nozzle and the translational movement of the nozzle is controlledsuch that the nozzle dispenses the material in a controlled manner toform a plurality of discrete elements on the paper contacting surface ofthe support structure.

In yet other aspects the present invention provides an additive processfor building a three-dimensional element on a support structurecomprising the steps of providing a support structure; providing anextrusion head coupled to a z gantry for dispensing a flowable materialselected from the group consisting of PET (polyester), PPS(polyphenylene sulphide), PCTA (poly 1,4 cyclohexane dimethyleneterephthalate), PEN (polyethylene naphthalate), PVDF (polyvinylidenefluoride) and PEEK (polyetheretherketone), either alone or incombination onto the belt; transporting extrusion head or the continuousbelt in the x and y directions while discharging the flowable materialfrom the extrusion head onto the belt to form the cross-sectional shapeof an element; and transporting the housing and head member in thez-direction simultaneously to form the element in elevation.

In other aspects the present invention provides a three-dimensionalpapermaking fabric comprising a support structure and a plurality of 3-Dprinted elements disposed thereon, the elements having a papercontacting surface lying in a first plane, a support structurecontacting surface lying in a second plane, a first aperture lying inthe first plane, a second aperture lying in the second plane and acontinuous channel joining the first and second apertures.

In still other aspects the present invention provides athree-dimensional papermaking fabric comprising a continuous papermakingbelt and a plurality of 3-D printed elements disposed thereon, theelements having a machine contacting surface and an opposed papercontacting surface and a pair of opposed sidewalls, the machinecontacting and paper contacting surfaces each having an aperture joinedby a continuous channel and at least one sidewall having an apertureconnected to an aperture on the machine contacting surface by acontinuous channel.

These and other aspects of the invention will now be more fullydescribed with reference to the drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a papermaking fabric accordingto one embodiment of the present invention;

FIG. 2 illustrates a cross-sectional view of an element of FIG. 1through the line 2-2;

FIG. 3 illustrates a perspective view of a papermaking fabric accordingto another embodiment of the present invention;

FIG. 4 illustrates a cross-sectional view of an element of FIG. 3through the line 4-4;

FIG. 5 illustrates a top view of a fabric useful in the manufacture oftissue webs according to one embodiment of the present disclosure;

FIG. 6 illustrates a cross-sectional view of a fabric taken through line6-6 of FIG. 5 ;

FIG. 7 illustrates a perspective view of a continuous fabric useful inthe manufacture of tissue webs according to one embodiment of thepresent disclosure;

FIG. 8 illustrates a belt comprising a plurality of discrete elementsaccording to one embodiment of the present invention; and

FIG. 9 illustrates a cross-sectional view of a belt taken through line9-9 of FIG. 8 .

DEFINITIONS

As used herein, the term “tissue product” refers to products made fromtissue webs and includes, bath tissues, facial tissues, paper towels,industrial wipers, foodservice wipers, napkins, medical pads, and othersimilar products. Tissue products may comprise one, two, three or moreplies.

As used herein, the terms “tissue web” and “tissue sheet” refer to afibrous sheet material suitable for forming a tissue product.

As used herein the term “element” refers to a material extending in thez-direction from the plane of a support structure.

As used herein the term “line element” refers to an element in the shapeof a line, which may be a continuous, discrete, interrupted, and/orpartial line with respect to a support structure on which it is present.The line element may be of any suitable shape such as straight, bent,kinked, curled, curvilinear, serpentine, sinusoidal and mixturesthereof.

As used herein the term “continuous line element” refers to a lineelement disposed on a support structure that extends withoutinterruption throughout one dimension of the support structure.

As used herein the terms “discrete element” and “protuberance” refer toseparate, unconnected elements disposed on a support structure. In oneexample, a plurality of discrete elements, such as dots and/or dashesfor example, may be arranged so as to form a decorative pattern.

As used herein the term “curvilinear decorative element” refers to anyline or visible pattern that contains either straight sections, curvedsections, or both that are substantially connected visually. Curvilineardecorative elements may appear as undulating lines, substantiallyconnected visually, forming signatures or patterns.

As used herein “decorative pattern” refers to any non-random repeatingdesign, figure, or motif. It is not necessary that the curvilineardecorative elements form recognizable shapes, and a repeating design ofthe curvilinear decorative elements is considered to constitute adecorative pattern.

As used herein the term “aperture” refers to an opening disposed on onesurface of a three-dimensional element or protuberance as disclosedherein.

As used herein, the term “solid free form fabrication” (SFF) generallyrefers to the three-dimensional printing of material using any one ofthe well-known layer manufacturing processes, such as stereolithography, selective laser sintering, inkjet printing, laminatedobject manufacturing, fused deposition modeling, laser-assisted weldingor cladding, and shape deposition modeling. SFF typically involvesrepresenting a 3-D object with a computer-aided design (CAD) geometryfile, converting the design file into a machine control command andusing the command to drive and control a part-building tool for buildingparts essentially point-by-point or layer-by-layer.

As used herein, the term “3-D printed” generally refers to a fuseddeposition modeling process (hereinafter abbreviated to FDM) asdescribed in U.S. Pat. No. 5,121,329, the contents of which are herebyincorporated by reference in a manner consistent with the presentdisclosure, and generally employs a heated nozzle to melt and extrudeout a material such as nylon, ABS plastic(acrylonitrile-butadiene-styrene) and wax. The build material issupplied into the nozzle in the form of a rod or filament.

As used herein, the term “printing head” means the entire device for theconveying, melting and application of a filament in an extrusion-based3-D printing process.

DETAILED DESCRIPTION

The present inventors have now surprisingly discovered that solid freeform fabrication may be used to produce novel paper machine clothinguseful in the manufacture of paper webs and more particularly tissuewebs. In particular the present inventors have discovered that solidfree form fabrication may be used to fabricate three-dimensionalelements on a support structure, such as a continuous woven papermakingbelt, that may in turn be used to produce a tissue product having asubstantially uniform density as well as visually discernible decorativeelements. Producing the three-dimensional elements by solid free formfabrication provides the benefit of being able to form apertures on boththe support structure and paper contacting surfaces of the elements andconnecting the apertures with continuous channels. These continuouschannels, which join the two surfaces of the elements facilitate removalof water from the wet paper web during production. Further, the elementsthemselves may impart the web with a three-dimensional pattern that isvisually distinctive.

With reference now to FIG. 1 an endless belt 10 comprising a pair ofelements 40 a, 40 b and a support structure 30 (also referred to hereinas a fabric) is illustrated. The support structure 30 has two principledimensions—a machine direction (“MD”), which is the direction within theplane of the belt 10 parallel to the principal direction of travel ofthe tissue web during manufacture and a cross-machine direction (“CD”),which is generally orthogonal to the machine direction. The supportstructure 30 is generally permeable to liquids and air. In oneparticularly preferred embodiment the support structure is a wovenfabric. The support structure may be substantially planar or may have athree-dimensional surface defined by ridges. In one embodiment thesupport structure is a substantially planar woven fabric such as amulti-layered plain-woven fabric 30 having base warp yarns 32 interwovenwith shute yarns 34 in a 1×1 plain weave pattern. One example of asuitable substantially planar woven fabric is disclosed in U.S. Pat. No.8,141,595, the contents of which are incorporated herein in a mannerconsistent with the present disclosure. In a particularly preferredembodiment the support structure 30 comprises a substantially planarwoven fabric wherein the plain-weave load-bearing layer is constructedso that the highest points of both the load-bearing shutes 34 and theload-bearing warps 32 are coplanar and coincident with the plane.

The support structure 30 comprises a pair of opposed major surfaces—aweb contacting surface 64 and a machine contacting surface 62. Machineryemployed in a typical papermaking operation is well known in the art andmay include, for example, vacuum pickup shoes, rollers, and dryingcylinders. In one embodiment the belt comprises a through-air dryingfabric useful for transporting an embryonic tissue web across dryingcylinders during the tissue manufacturing process. In such embodimentsthe web contacting surface 64 supports the embryonic tissue web, whilethe opposite surface, the machine contacting surface 62, contacts thethrough-air dryer.

With further reference to FIG. 1 the elements 40 a, 40 b are generallyaffixed to the support structure and extend in the z-direction away fromthe plane 50 of the support structure 30 to form part of the webcontacting surface 64. Generally the elements 40 a, 40 b are disposed onthe support structure 30 using solid free form fabrication, which willbe discussed in more detail below, and comprise a plurality of apertures41 a, 41 b disposed along their upper surface 48 which generally liesabove the plane 50 of the support structure 30 and forms part of the webcontacting surface 64.

In addition to elements 40 a, 40 b, the web-contacting surface 64preferably comprises a plurality of landing areas 60. The landing areas60 are generally bounded by the elements 40 a, 40 b and coextensive withthe top surface plane 50 of the belt 10. Landing areas 60 are generallypermeable to liquids and allow water to be removed from the cellulosicfibrous structure by the application of differential fluid pressure, byevaporative mechanisms, or both when drying air passes through theembryonic tissue web while on the papermaking belt 10 or a vacuum isapplied through the belt 10. Without being bound by any particularlytheory, it is believed that the arrangement of elements and landingareas allow the molding of the embryonic web causing fibers to deflectin the z-direction and generate the caliper of, and aesthetic patternson, the resulting tissue web.

Turning now to FIG. 2 an element 40 generally has a bottom surface 44lying in a first plane. The bottom surface generally forms the contactbetween the support structure and the element. Opposed to the bottomsurface 44 is a top surface 48 lying in a second plane above the firstplane. The bottom 44 and top 48 surfaces are joined by a pair of opposedsidewalls 45, 47 resulting in the illustrated element 40 having a height(h) and a width (w). Accordingly, in the illustrated embodiment, theelement 40 has generally planar sidewalls 45, 47 and a squarecross-section where the width (w) and height (h) are equal. In suchembodiments w and h may vary from about 0.6 to about 3.0 mm, in aparticularly preferred embodiment w and h may vary from about 0.7 toabout 1.4 mm and still more preferably from about 0.8 to about 1.0 mm.While the illustrated element has a square cross-section, the inventionis not so limited, as will be discussed in more detail below.

In addition to having square cross-sections, such as illustrated in FIG.2 , the element cross-section may be rectangular, trapezoidal,triangular, convex or concave. For example, the elements may comprisegenerally planar bottom and top surfaces joined by sidewalls thatconverge towards one another as they extend from the bottom to the topsurface, resulting in an element having a trapezoidal cross-section.Further, the elements 40 may have a width (w) greater than about 0.5 mm,such as from about 0.5 to about 3.5 mm, more preferably from about 0.7to about 1.4 mm, and in a particularly preferred embodiment between fromabout 0.8 to about 1.0 mm. The width is generally measured normal to theprincipal dimension of the elevation within the plane of the belt at agiven location. Where the element 40 has a generally square orrectangular cross-section, the width (w) is generally measured as thedistance between the two planar sidewalls 45, 47 that form the element40. In those cases where the element does not have planar sidewalls, thewidth is measured along the base of the element at the point where theelement contacts the carrier.

As illustrated in FIG. 2 the elements 40 may comprise a pair of opposedapertures 41, 42 joined by a continuous channel 43. The first aperture41 is disposed on the top surface 48 of the element 40 and a secondaperture 42 is disposed on the bottom surface 44. The apertures 41, 42are joined by a continuous channel 43 that generally extends through theelement 40 creating a continuous passageway between the bottom 44 andtop surface 48. Preferably the continuous channel 43 is shaped so as topermit the passage of air and/or water through the element. In certainembodiments the channel 43 may have a horizontal cross-section that isessentially circular, oval, triangular, square, rectangular, pentagonal,or hexagonal. The apertures may have similar or different horizontalcross-sections relative to one another and the channel that joins them.In the embodiment illustrated in FIG. 2 both the apertures 41, 42 andthe channel 43 have a rectangular horizontal cross-section.

Just as the horizontal cross-sectional shape of the aperture may vary,the volume of the aperture may vary depending on desired permeability ofthe belt. For example, in certain embodiments the apertures may have avolume of about 20 percent or greater of the volume of the element, suchas from about 20 to about 90 percent and more preferably from about 50to about 90 percent. The length of the channel may vary as it may takevariety of paths to connect a pair of opposed apertures, however in apreferred embodiment the channel is substantially linear and has alength that is essentially the same as the height of the element.

Where the apertures and channels are substantially similar in size andshape, such as having substantially rectangular horizontalcross-section, the width (w) may be about 0.1 mm or greater, such asfrom about 0.1 to about 3.0 mm and more preferably from about 0.1 toabout 2.0 mm. The channel sidewalls, illustrated in FIG. 2 as s, aregenerally thick enough to resist deformation in use, such as greaterthan about 0.08 mm, such as from about 0.08 to about 0.5 mm and morepreferably from about 0.10 to about 0.2 mm. The size of the apertures,as well as the channel connecting them, may be varied to achieve thedesired web dewatering and drying properties as well as the aestheticsof the resulting web. For example, by suitable choice of aperturedimensions and shape, the degree of visibility of the aperture patternin the resulting tissue may be made as faint or as distinct as desired.

With reference now to FIG. 3 , in other embodiments, elements 40 a, 40 bmay comprise one or more apertures 46 disposed along one or both of theelement sidewalls 45, 47. Like the apertures 41 a, 41 b disposed alongthe top surface 48 of the element, and discussed above, the sidewallaperture 46 may have any number of different cross-section shapes,including a rectangular cross-section as illustrated in FIG. 3 . Thesidewall aperture 46 is generally connected to an aperture 42 disposedon the bottom surface 44 of the element 40. As best illustrated in FIG.4 , a continuous channel 43 joins the sidewall aperture 46 a and thebottom surface aperture 42 a creating a continuous passageway betweenthe sidewall 47 and the bottom 44 of the element. In this manner, as theweb is molded around the element during manufacture water may pass fromthe web in contact with the sidewall, through the element and exit thebottom. Without being bound by any particular theory it is believed thatthis additional passageway for water enhances drying and improvesmolding of the embryonic web.

In addition to taking any number of different cross-sectional shapes,the sidewall apertures may be spaced and arranged along the elementsidewalls in a variety of patterns to improve drying efficiency andmaximize molding of the web. For example, in one embodiment the sidewallaperture is orientated substantially in parallel to the plane of theweb-contacting surface of the support structure. Further, the sidewallapertures may be located along any height of the element, however, incertain embodiments to improve the molding of the tissue web theapertures are disposed along the lower third of the element and morepreferably adjacent to the point at which the element contacts thesupport structure.

Turning now to FIG. 5 , the endless belt 10 may comprise a plurality ofelements 40 a-40 d oriented substantially in the MD direction and spacedapart from one another across the CD direction of the support structure30. The elements 40 a-40 d are illustrated as being continuous lineelements and more specifically continuous line elements having asinusoidal or wave-like shape, however, the invention is not so limited.The elements 40 a-40 d generally extend in the z-direction away from theplane 50 of the support structure 30 to form part of the web contactingsurface 64. The elements 40 a-40 d comprise a plurality of apertures 41along their top surface 48, which forms part of the web contactingsurface 64. As discussed above, the aperture 41 is preferably incommunication with an aperture on the bottom surface of the element viaa continuous channel. In this manner when the belt 10 is supporting aweb during manufacture the web is brought in contact with the topsurface 48 and water may pass through the apertures 41 and betransported through the element to the bottom surface (not illustratedin FIG. 5 ) to facilitate dewatering of the web.

The spacing and arrangement of the elements may vary depending on thedesired tissue product properties and appearance. In one embodiment,such as that illustrated in FIG. 5 , a plurality of elements 40 a-40 dextend continuously throughout one dimension of the belt 10 and eachelement is spaced apart from adjacent element. Thus, the elements may bespaced apart across the entire cross-machine direction of the belt, mayendlessly encircle the belt in the machine direction, or may rundiagonally relative to the machine and cross-machine directions. Ofcourse, the directions of the elements alignments (machine direction,cross-machine direction, or diagonal) discussed above refer to theprincipal alignment of the elements. Within each alignment, the elementsmay have segments aligned at other directions, but aggregate to yieldthe particular alignment of the entire elements.

The spaced apart elements 40 a-40 d form landing areas 60 there between,which together with the elements generally make up the web contactingsurface 64 of the belt 10. In use, as the embryonic tissue web is formedfibers are deflected in the z-direction by the continuous elements,however, the spacing of elements is such that the web maintains arelatively uniform density. This arrangement provides the benefits ofimproved web extensibility, increased sheet bulk, better softness, and amore pleasing texture. These properties may be influenced varying thepercentage elements constituting the web contacting surface. Forexample, in certain embodiments, the spacing and arrangement may beadjusted such that the elements constitute greater than about 15 percentof the web contacting surface, such as from about 15 to about 35percent, more preferably from about 18 to about 30 percent, and stillmore preferably from about 20 to about 25 percent of the web-contactingsurface.

An additional means of altering the physical properties of manufacturedwebs, such as caliper, density and cross-machine direction stretch andtoughness, is to alter the shape of the element and particularly theshape of line elements, as well as the spacing and arrangement of lineelements relative to one another. For example, the line element may havea wave-like pattern where the line elements are arranged in-phase withone another such that P (the distance between adjacent elements measuredfrom the center of one element to the center of the adjacent element) isapproximately constant. In other embodiments elements may form a wavepattern where adjacent elements are offset from one another. In stillother embodiments the line elements may be linear. In other embodimentsthe elements may be linear and form a pattern having adjacent linearelements that alternate between a maximum spacing when the line elementsdiverge away from each other and minimum spacing when the line elementsconverge toward each other. In a particularly preferred embodiment,regardless of the particular element pattern, or whether adjacentpatterns are in or out of phase with one another, the elements areseparated from one another by some minimal distance.

In one preferred embodiment, such as that illustrated in FIG. 5 , theelements 40 a-40 d are continuous line elements having a sinusoidalshape and are arranged substantially parallel to one another such thatnone of the elements intersect one-another. As such, in the illustratedembodiment, the adjacent sidewalls of individual elements are equallyspaced apart from one another. In such embodiments, the center-to-centerspacing of design elements (also referred to herein as pitch or simplyas p) may be greater than about 1.0 mm, such as from about 1.0 to about20 mm apart and more preferably from about 2.0 to about 10 mm apart. Inone particularly preferred embodiment the continuous elements are spacedapart from one-another from about 3.8 to about 4.4 mm. Without beingbound by any particular theory it is believed that this spacing andarrangement of sinusoidal elements results in improved caliper andcross-machine direction tensile properties, such as stretch. Further,this arrangement provides a tissue web having a three-dimensionalsurface topography, yet relatively uniform density.

Where the elements have a wave-like shape, such as those illustrated inFIG. 5 , the elements 40 a-40 d have an amplitude (A) and a wavelength(L). The amplitude may range from about 2.0 to about 200 mm, in aparticularly preferred embodiment from about 10 to about 40 mm and stillmore preferably from about 18 to about 22 mm. Similarly, the wavelengthmay range from about 20 to about 500 mm, in a particularly preferredembodiment from about 50 to about 200 mm and still more preferably fromabout 80 to about 120 mm.

Turning to FIG. 6 , which illustrates a cross-sectional view of apapermaking fabric according to one embodiment of the present invention.The fabric generally comprises a web contacting surface 64 and a machinecontacting surface 62. The web contacting surface 64 comprises landingareas 60 generally bounded by elements 40 a, 40 b, 40 c which extend inthe z-direction from the the top surface plane 50 of the belt. Theelements 40 a, 40 b, 40 c comprise apertures 41 which have a continuouschannel 43 that extends to the bottom surface aperture 42 creating acontinuous passageway between the top and the bottom of the element. Theelements 40 generally have a height (h), measured between the top plane50 of the belt and the top plane 52 of the element, and a width (w),measured between the element sidewalls. Further, the elements are spacedapart from one another a distance (p), which is measured between themid-points of adjacent elements.

In a particularly preferred embodiment, such as that illustrated in FIG.7 , the elements 40 a-40 d are continuous line elements and extendsubstantially throughout one dimension of the belt 10, and each lineelement in the plurality is spaced apart from adjacent elements. In thismanner the elements may span the entire cross-machine direction of thebelt or may endlessly encircle the belt in the machine direction. As thecontinuous elements generally extend substantially throughout onedimension of the belt they are distinguishable from patterns formed froma plurality of discrete elements, which is another embodiment of thepresent invention and will be discussed in further detail below. Thus,in certain embodiments the landing areas provide a visually distinctiveinterruption to the first and second continuous line elements whichextend substantially in the machine direction orientation.

Turning now to another embodiment of the present invention where theelements are discrete, rather than continuous as described above. Forclarity, the discrete elements will be referred to herein asprotuberances. Protuberances according to various embodiments of thepresent invention are illustrated in FIGS. 8 and 9 . Generally theprotuberances 80 a-80 c are discrete and spaced apart from one another.Each protuberance 80 a-80 c is joined to a support structure 90 andextends outwardly from the web contracting plane 92 thereof. Theprotuberances 80 a-80 c terminate in an upper surface 82 that lies in asecond plane 96 above the plane 92 of the support structure 90. Thedifference between the two planes 92, 96 is generally representative ofthe height of the protuberance (h). In this manner the web contactingsurface 98 comprises the web facing surface 91 and upper surface 82 ofthe protuberances 80 a-80 c and has two principle planes 92, 96 lying intwo different elevations.

The protuberances 80 a-80 c illustrated in FIG. 9 generally have asquare horizontal and lateral (relative to the plane 92 of the supportstructure 90) cross-sectional shape, however, the shape is not solimited. The protuberances 80 a-80 c may have any number of differenthorizontal and lateral cross-sectional shapes. For example, thehorizontal cross-section may have a rectangular, circular, oval,polygonal or hexagonal shape. Further, a single belt may compriseprotuberances having the same or different cross-sectional shapes. Aparticularly preferred protuberance is substantially square shapedhaving sidewalls that are generally perpendicular to the plane of thesupport structure. Alternatively, the protuberances may have a taperedlateral cross-section formed by sides that converge to yield aprotuberance having a base that is wider than the distal end.

In certain embodiments the individual protuberances may be arranged tocreate a decorative pattern. In one particular embodiment, such as thatillustrated in FIG. 8 , protuberances 80 a-80 c are spaced and arrangedin a non-random pattern so as to create a wave-like decorative pattern98. The belt 100 comprises a plurality of decorative patterns 98 a, 98 bthat are substantially orientated in the machine direction and spacedapart from one another. As a result of the spacing and arrangement ofdecorative patterns 98 a, 98 b, landing areas 102 are created betweenadjacent patterns 98 a, 98 b. The landing areas 102 provide a visuallydistinctive interruption to the decorative pattern 98 formed by theindividual spaced apart protuberances 80 a-80 c. In this manner, despitebeing discrete elements, the protuberances 80 a-80 c may be spaced apartso as to form a visually distinctive curvilinear decorative pattern thatextends substantially in the machine direction. Thus, in certainembodiments, taken as a whole the discrete elements form a wave-likedecorative pattern. The wave-like decorative pattern may have dimensionssimilar to those described above for line elements forming wave-likepatterns, such as an amplitude from about 10 to about 40 mm and awavelength from about 50 to about 200 mm. Further the individualwave-like patterns may be spaced apart from one another from about 1.0to about 20 mm apart and more preferably from about 2.0 to about 10 mmapart.

In other embodiments the protuberances may be spaced and arranged so asto form a decorative figure, icon or shape such as a flower, heart,puppy, logo, trademark, word(s) and the like. Generally the designelements are spaced about the support structure and can be equallyspaced or may be varied such that the density and the spacing distancemay be varied amongst the design elements. For example, the density ofthe design elements can be varied to provide a relatively large orrelatively small number of design elements on the web. In a particularlypreferred embodiment the design element density, measured as thepercentage of background surface covered by a design element, is fromabout 10 to about 35 percent and more preferably from about 20 to about30 percent. Similarly the spacing of the design elements can also bevaried, for example, the design elements can be arranged in spaced apartrows. In addition, the distance between spaced apart rows and/or betweenthe design elements within a single row can also be varied.

While the protuberances may be spaced and arranged so as to form adecorative pattern, adjacent protuberances are generally spaced apartfrom one another so as to create spaces there-between. Depending uponthe arrangement and spacing of individual protuberances relative to oneanother the inter-protuberance spaces may or may not occur as voids thatare permeable to air and liquid. In certain embodiments the space may beentirely devoid of yarns used to form the support structure, may bepartially obscured by a yarn or may be entirely obscured by a yarn.Thus, the spaces may have varying degrees of air and liquidpermeability. In certain embodiments where the belt is a through-airdrying fabric used to support an embryonic tissue web during drying itmay be desirable to provide a high percentage of spaces entirely orsubstantially devoid of yarns and protuberances so as to facilitate thepassage of air through the fabric and subsequently the embryonic web. Insuch embodiments the presence of areas entirely devoid of protuberancesand yarn may improve drying efficiency. As the spaces are defined by thespace between adjacent protuberances they may generally vary in widthfrom about 0.1 to about 1 mm, such as from about 0.2 to about 0.6 mm andmore preferably from about the 0.25 to about 0.5 mm.

The size of the protuberances and the spacing between adjacentprotuberances may be the same throughout a given design or an entirebelt or it may be varied throughout a design or the entire belt. Forexample, a design may be formed by protuberances having two, three, fouror five different sizes where the space between the protuberances variesdepending on the relative size of the adjacent protuberances. Thus, incertain embodiments the ratio of the surface area of protuberances andthe width of the spaces may range from about 5:1 to about 1:2, such asfrom about 4:1 to about 1:1.

With reference to FIG. 9 , when protuberances 80 a-80 c are spaced apartfrom one another they define landing areas 102 there-between. Thelanding areas 102 are generally bounded by the protuberances 80 a-80 cand coextensive with the top surface plane 92 of the support structure90. Landing areas 102 are generally permeable to liquids and allow waterto be removed from the cellulosic fibrous structure by the applicationof differential fluid pressure, by evaporative mechanisms, or both whendrying air passes through the embryonic tissue web while on thepapermaking belt 100 or a vacuum is applied through the belt 100.

The elements of the present invention, including line elements anddiscrete protuberances, are generally formed by depositing a polymericmaterial on the support structure in any suitable manner. Thus incertain embodiments elements are formed by extruding, such as thatdisclosed in U.S. Pat. No. 5,939,008, the contents of which areincorporated herein by reference in a manner consistent with the presentdisclosure, or printing, such as that disclosed in U.S. Pat. No.5,204,055, the contents of which are incorporated herein by reference ina manner consistent with the present disclosure, a polymeric materialonto the support structure. In other embodiments the design element maybe produced, at least in some regions, by extruding or printing two ormore polymeric materials.

In one embodiment the elements are formed using SFF or layermanufacturing (LM) techniques, such as 3-D printing techniques describedin U.S. Pat. No. 5,204,055. Generally, 3-D printing techniques may beemployed to form an element from a series of layers of material witheach layer printed and formed on top of the previous layer.

Three-dimensional printing of the elements generally begins withcreating a computer model of the element in three dimensions using asuitable computer modeling program known in the art. The computer modelof the element is completely sectioned into a series of horizontaldigital slices to define a set of slice patterns for each layer.

In one embodiment the elements may be formed using one or moreprintheads that span at least a portion of the width of the belt. Theprintheads may be moveable so as to print materials onto a static belt,or the belt may be moved and the printheads may be fixed. Regardless, itis generally preferred that the moving object be moved at asubstantially constant speed in a flat plane. In one particularlypreferred embodiment a plurality of printheads extend across the widthof the belt, which is moved in a flat plane during printing,perpendicular to the direction of travel of the belt and are,preferably, spaced along the belt with substantially constantseparations. However, constant separation of the printheads is notcritical.

The printheads print one layer of an object onto the previously printedlayer. Thus the first printhead prints the first layer, the secondprinthead prints a second layer onto the first layer and the Nthprinthead prints an Nth layer onto the (n−1)th layer.

The layers are of a constant thickness and the printheads are controlledso that, in plane view, layers are printed on top of each other. Thedistance from each of the printheads to the surface upon which theyprint is also preferably the same for all printheads. Thus the distancefrom the first printhead to the substrate is preferably the same as thedistance from the seventh printhead to the sixth layer. This may beachieved by sequentially raising the printhead(s) for each layer by thevoxel height. In this situation, droplets ejected by printheads fordifferent layers at exactly the same time will arrive at theirdestinations at the same time.

In certain embodiments the elements may be formed with an aperture. Theapertures generally function as fluid passageways or for other purposesand remain ‘empty’ of printed or inserted materials in the finishedproduct. It will be appreciated that the aperture may vary in shape andmay include squares, rectangles, ovals and circles, and polygons havingan odd number of sides. The apertures may be the same or differentshapes and may be the same or different size. In particularly preferredembodiments an aperture is disposed on at least two different surfacesof an element and the apertures are connected to one another by acontinuous channel. The continuous channel places the pair of aperturesin communication with one another and creates a passageway through theelement.

The printing system may comprise a means for moving the belt as it isprinted. Preferably the belt is moved at a substantially constantvelocity in a flat plane. The belt may be directly driven or may belocated on a conveyor system.

The materials printed by the printheads may include photo-curable andself-curing resins. Photocurable resins may include resins curable by UVcuring, visible light curing, electron beam curing, gamma radiationcuring, radiofrequency curing, microwave curing, infrared curing, orother known curing methods involving application of radiation to cure aresin. Suitable resins may also include those that may be cured viachemical reaction without the need for added radiation as in the curingof an epoxy resin, extrusion of an autocuring polymer such aspolyurethane mixture, thermal curing, solidifying of an applied hotmeltor molten thermoplastic.

In certain embodiments the polymeric material may comprise PET(polyester), PPS (polyphenylene sulphide), PCTA (poly 1,4 cyclohexanedimethylene terephthalate), PEN (polyethylene naphthalate), PVDF(polyvinylidene fluoride) or PEEK (polyetheretherketone), either aloneor in combination. Generally, such materials are capable of withstandingcontinuous service up to 500° F. in the presence of air and water vapor.

In other embodiments the polymeric material comprises a thermoplasticssuch as, for example, a thermoplastic comprising from about 0.5 and 10weight percent silicone and a base polymer selected from the groupconsisting of polyethersulfones, polyetherimides, polyphenylsulfones,polyphenylenes, polycarbonates, high-impact polystyrenes, polysulfones,polystyrenes, acrylics, amorphous polyamides, polyesters, nylons, PEEK,PEAK and ABS.

In still other embodiments the materials may comprise a polymericmaterial having a viscosity greater than 70,000 Centipoise (cP) andpreferably in a range from about 100,000 to about 150,000 cP, measuredaccording to ASTM D790-10 at 120° C. In certain preferred embodimentsthe polymer material comprises at least one of a polyurethane, asilicone, or a polyureas and has a viscosity from about 120,000 to about140,000 cP.

In one preferred embodiment the belt of the present invention isprepared by an LM method comprising an extrusion head that extrudesheated, flowable modeling material from a nozzle onto a supportstructure. The extruded material is deposited layer-by-layer in areasdefined from a CAD model, as the extrusion head and the supportstructure are moved relative to each other in three dimensions by anx-y-z gantry system. The material solidifies after it is deposited toform a three-dimensional element. The material may be a thermoplasticmaterial which solidifies after deposition by cooling.

Extrusion heads and systems suitable for preparing three-dimensionalelements as described above are commercially available from StratasysFDM® modeling machines. The extrusion head, which includes a liquifierand a dispensing nozzle, receives modeling material in a solid form. Thefilament is heated to a flowable temperature inside the liquifier and itis then dispensed through the nozzle. Thermoplastic materials,particularly ABS thermoplastic, have been found particularly suitablefor deposition modeling in the Stratasys FDM® modeling machines. Acontroller controls movement of the extrusion head in a horizontal x, yplane, controls movement of the build platform in a verticalz-direction, and controls the feeding of modeling material into thehead. By controlling these processing variables, the modeling materialis deposited at a desired flow rate in “beads” or “roads” layer-by-layerin areas defined from the CAD model to create a three-dimensional objectthat resembles the CAD model. The modeling material thermallysolidifies, and the finished model is removed from the substrate.

Having now described the present invention with references to theattached figures, it will be appreciated that in a first embodiment thepresent invention provides a papermaking belt comprising a supportstructure and a three-dimensional element attached to the supportstructure and extending in the z-direction therefrom, the supportstructure and the three-dimensional element consisting of differentmaterials and wherein the three-dimensional element is formed by solidfree form manufacturing or layer manufacturing.

In a second embodiment the present invention provides the papermakingbelt of the first embodiment wherein the element is formed layer bylayer, in a stepwise fashion, out of a flowable polymeric material froma printing head onto a woven support structure.

In a third embodiment the present invention provides the papermakingbelt of the first or the second embodiment wherein the three-dimensionalelement is a line element having a top surface and an opposing bottomsurface, a first and a second aperture disposed on the top and bottomsurfaces and a continuous channel connecting the first and the secondapertures.

In a fourth embodiment the present invention provides the papermakingbelt of the first through the third embodiments wherein thethree-dimensional element is a line element having a substantiallyrectangular cross-sectional shape.

In a fifth embodiment the present invention provides the papermakingbelt of the first through the fourth embodiments wherein thethree-dimensional element is a line element having a sidewall, a bottomsurface, a first and a second aperture disposed on the sidewall and thebottom surface and a continuous channel connecting the first and thesecond apertures.

In a sixth embodiment the present invention provides the papermakingbelt of the first through the fifth embodiments wherein the beltcomprises a plurality of substantially machine-direction orientedcontinuous three-dimensional line elements parallel to, and spaced apartfrom, one another.

In a seventh embodiment the present invention provides the papermakingbelt of the sixth embodiment wherein the plurality of substantiallymachine-direction oriented continuous three-dimensional line elementshave a sinusoidal shape having a wavelength from about 50 to about 200mm and an amplitude from about 10 to about 40 mm and having a spacing(P) from about 2.0 to about 10 mm apart.

In an eighth embodiment the present invention provides an endlesspapermaking belt comprising a support structure having a machine andcross-machine direction and a machine contacting and an opposed uppersurface; and a plurality of additively manufactured line elementsdisposed on the upper surface of the support structure, the lineelements having a top surface, a bottom surface a pair of opposedsidewalls, a first aperture disposed on the top surface and a secondaperture disposed on the bottom surface and a continuous channelconnecting the first and second apertures.

In a ninth embodiment the present invention provides the endlesspapermaking belt of the eighth embodiment wherein the line elements arecontinuous and orientated in the machine direction of the supportstructure and are equally spaced apart from one another.

In a tenth embodiment the present invention provides the endlesspapermaking belt of the eighth or the ninth embodiment wherein the lineelements have a rectangular cross-section.

In an eleventh embodiment the present invention provides the endlesspapermaking belt of the eighth through the tenth embodiments wherein theline elements have a height from 0.5 to about 3.5 mm and width fromabout 0.5 to about 3.5 mm.

In a twelfth embodiment the present invention provides the endlesspapermaking belt of the eighth through the eleventh embodiments whereinthe line elements and upper surface of the support structure comprisethe web contacting surface and wherein the line elements comprise fromabout 15 to about 35 percent of the surface area of the web contactingsurface.

In a thirteenth embodiment the present invention provides the endlesspapermaking belt of the eighth through the twelfth embodiments whereinthe line elements comprise a plurality of opposed apertures disposed onthe top and bottom surfaces, the opposed apertures connected to oneanother by a continuous channel, wherein the apertures comprise fromabout 20 to about 90 percent of the total top surface area of theelement.

In a fourteenth embodiment the present invention provides the endlesspapermaking belt of the eighth through the thirteenth embodimentswherein the apertures have a cross-section area from about 0.05 to about0.5 mm².

In an fifteenth embodiment the present invention provides the endlesspapermaking belt of the eighth through the fourteenth embodimentsfurther comprising an aperture disposed on at least one sidewall, theaperture connected to the aperture disposed on the bottom surface by acontinuous channel.

We claim:
 1. A papermaking belt comprising a support structure and athree-dimensional element attached to the support structure andextending in the z-direction therefrom, the element having at least oneaperture, the support structure and the three-dimensional elementconsisting of different materials and wherein the three-dimensionalelement is comprises a plurality of layers formed by solid free formmanufacturing or layer manufacturing.
 2. The papermaking belt of claim 1comprising a plurality of discrete elements spaced apart from oneanother and arranged to form a decorative pattern.
 3. The papermakingbelt of claim 2 wherein the discrete elements have a rectangular crosssection, a height from about 0.5 to about 3.5 mm and width from about0.5 to about 3.5 mm and are spaced apart from one another at least about1.0 mm.
 4. The papermaking belt of claim 1 wherein the support structurehas a machine and cross-machine direction and the elements arecontinuous line elements and orientated in the machine direction of thesupport structure and are equally spaced apart from one another.
 5. Thepapermaking belt of claim 4 wherein the line elements have a rectangularcross-section.
 6. The papermaking belt of claim 4 wherein the lineelements have a height from about 0.5 to about 3.5 mm and width fromabout 0.5 to about 3.5 mm.
 7. The papermaking belt of claim 4 whereinthe line elements and upper surface of the support structure comprisethe web contacting surface and wherein the line elements comprise fromabout 15 to about 35 percent of the surface area of the web contactingsurface.
 8. The papermaking belt of claim 4 wherein the line elementscomprise a plurality of opposed apertures disposed on the top and bottomsurfaces, the opposed apertures connected to one another by a continuouschannel, wherein the apertures comprise from about 20 to about 90percent of the total top surface area of the element.
 9. The papermakingbelt of claim 4 wherein the at least one aperture has a cross-sectionarea from about 0.05 to about 0.5 mm².
 10. The papermaking belt of claim4 further comprising an aperture disposed on at least one sidewall, theaperture connected to the aperture disposed on the bottom surface by acontinuous channel.